Method for controlling current in a load

1. A control system, comprising:

a controller configured to drive a load based on a set-point of the load, and further configured to measure a load characteristic of the load, and compute an average load characteristic, and to determine a corrected set-point based on the computed average,

wherein the controller is configured to determine the corrected set-point by comparing the average load characteristic to an initial set-point, and summing the result thereof with the initial set-point and a hysteretic band value, and

wherein the controller is further configured to drive the load in response to the corrected set-point.

2. The system of claim 1 , wherein the load characteristic is one of a load current, a voltage, a magnetic field, a light energy, and a power of the load.

3. The system of claim 1 , wherein the controller further comprises a dither generator configured to generate a dither signal to provide substantially continuous motion to the load when operably coupled thereto, and provide a time base source for the average load characteristic computation, wherein the controller computes the average load characteristic over an integer number of dither cycles.

4. The system of claim 1 , wherein the average load characteristic is computed over an integer number of load switching cycles.

5. The system of claim 1 , wherein the controller is further configured to digitally measure the load characteristic of the load.

6. A compensated hysteretic control system, comprising:

measurement means for measuring a load characteristic associated with a load;

output means for driving the load according to a set-point of the load; and

control means for computing an average load characteristic from the measured load characteristic and determining a corrected set-point,

wherein the control means is configured to determine the corrected set-point by comparing the average load characteristic to an initial set-point, and summing the result thereof with the initial set-point and a hysteretic band value, and

wherein the output means drives the load in response to the corrected set-point.

7. The system of claim 6 , wherein the load characteristic is one of a load current, a voltage, a magnetic field, a light energy, and a power of the load.

8. The system of claim 6 , wherein the control means is further configured to generate a dither signal to provide substantially continuous motion to the load when operably coupled thereto, wherein the dither signal provides a time base for the average load characteristic computation, and wherein the controller computes the average load characteristic over an integer number of dither cycles.

9. The system of claim 6 , wherein the average load characteristic is computed over an integer number of load switching cycles.

10. The system of claim 6 , wherein the control means is further configured to digitally measure the load characteristic of the load.

11. A control system, comprising:

a controller configured to digitally measure a load characteristic of a load at an input thereof, and further configured to drive the load based on a set-point of the load; and

a correction circuit configured to compute an average load characteristic using the measured load characteristic over an integer number of cycles, and further configured to determine a corrected set-point by comparing the average load characteristic to an earlier set-point, and summing the result thereof with the initial set-point and a hysteretic band value;

wherein the controller is further configured to drive the load in response to the corrected set-point determined by the correction circuit.

12. The system of claim 11 , wherein the load characteristic is one of a load current, a voltage, a magnetic field, a light energy, and a power of the load.

13. The system of claim 11 , wherein the correction circuit further comprises a dither generator configured to generate a dither signal to provide substantially continuous motion to the load when operably coupled thereto, and provide a time base source for computing the average load characteristic over an integer number of dither cycles.

14. The system of claim 11 , wherein the average load characteristic is computed over an integer number of load switching cycles.

15. The system of claim 11 , wherein the hysteretic band value corresponds to an ON or OFF status of the load driver.

16. A method of controlling an average current in a load comprising:

measuring a load characteristic associated with the load when driven at a set-point;

generating a dither signal to provide substantially continuous motion to the load when operably coupled thereto;

computing an average load characteristic based on the load characteristic measurement over an integer number of dither cycles;

determining a corrected set-point based on the average load characteristic computation; and

driving the load in response to the corrected set-point.

17. The method of claim 16 , wherein the load characteristic is one of a load current, a voltage, a magnetic field, a light energy, and a power of the load.

18. The method of claim 16 , wherein measuring the load characteristic comprises digitally measuring the load characteristic of the load.

19. The method of claim 18 , wherein computing an average load characteristic comprises using and averaging the measured load characteristic over an integer number of cycles.

20. The method of claim 19 , wherein determining a corrected set-point comprises comparing the average load characteristic to an initial set-point, and summing the result thereof with the initial set-point and a hysteretic band value.

21. The method of claim 20 , wherein the hysteretic band value corresponds to an ON or OFF status of the load driving.